Boom! by Mark Haddon

Two school friends bug their teachers’ lounge and overhear a bizarre, unearthly language, uncovering a secret that some staff are aliens in disguise. When one of them is abducted, the other teams up with a tough older sister and her biker boyfriend for a frantic chase from city streets to remote highlands and through a portal to another world. Fast, funny, and frantic, this sci-fi caper turns everyday kids into unlikely heroes as they decode the alien plot and risk everything to bring their friend home.

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